docs: def cdf_discrete(self, ds, n=None):
          r'''Computes the cumulative distribution functions for a list of 
          specified particle diameters.
                                          
          Parameters
          ----------
          ds : list[float]
              Particle size diameters, [m]
          n : int, optional
              None (for the `order` specified when the distribution was created),
              0 (number), 1 (length), 2 (area), 3 (volume/mass),
              or any integer, [-]
  
          Returns
          -------
          cdfs : float
              The cumulative distribution functions at the specified diameters 
              and order, [-]
          
          Examples
          --------
          >>> psd = PSDLognormal(s=0.5, d_characteristic=5E-6, order=3)
          >>> psd.cdf_discrete([1e-6, 1e-5, 1e-4, 1e-3])
          [0.0006434710129138987, 0.9171714809983015, 0.9999999989602018, 1.0]
          '''
          return [self.cdf(d, n=n) for d in ds]